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National Antimicrobial Resistance Monitoring System
(NARMS) Frequently Asked Questions (FAQ) About Antibiotic
Resistance - Why are bacteria becoming resistant to
antibiotics? |
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NARMS Home
> FAQ
Antibiotic Resistance
> Why
are bacteria becoming resistant to antibiotics?
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Antibiotics kill or inhibit the growth of susceptible
bacteria. Sometimes one of the bacteria survives because
it has the ability to neutralize or evade the effect
of the antibiotic; that one bacteria can then multiply
and replace all the bacteria that were killed off. Exposure
to antibiotics therefore provides selective pressure,
which makes the surviving bacteria more likely to be
resistant. In addition, bacteria that were at one time
susceptible to an antibiotic can acquire resistance
through mutation of their genetic material or by acquiring
pieces of DNA that code for the resistance properties
from other bacteria. The DNA that codes for resistance
can be grouped in a single easily transferable package.
This means that bacteria can become resistant to many
antimicrobial agents because of the transfer of one
piece of DNA. |
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Date:
June 1, 2005
Content source: National Center for Zoonotic, Vector-Borne, and Enteric Diseases (ZVED)
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